A little known trick in Windows '95 is that you can hide the task bar.
Simply right-click on an empty part of the task bar and choose
properties. (Or: Click Start; Click Settings; Click Task Bar) Choose
the auto-hide option.

Now, unless your mouse is over where the task bar
would be, the task bar can't tell on you if your boss stops by. Just open up your normal work program(s), then connect to the Internet.
Maximize your work program and then run your browser. If you press
ALT-TAB, you will switch to another application. Make sure that when you
travel from your work app to your browser it's as quick as hitting
ALT Tab to switch to your work. Then, after he leaves, resume browsing.